2015-2021 Mercedes-Benz C-Class W205 — subwoofer box fitment

What we researched for this specific generation: where an enclosure actually fits, what the factory speakers are, how the factory audio is wired, and which real builds and commercial products exist for it. Confidence badges say how well each figure is sourced — this is research, not manufacturer spec.

Body styles covered: 4-Door Sedan

Where a box actually fits

These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.

Standard Likely

Locationfactory footwell locations (JL Audio 8" drops directly in) or trunk, squeezed against the rear seatback
Outer bounding boxNot independently measured — factory-shaped footwell cavity confirmed to accept an 8" driver directly
Known obstructionsNone specifically documented beyond the cavity's fixed factory shape
Usable volume estimate0.5 ft³

Starting points

Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.

Budget

Subwoofers1x8" trunk build, squeezed against rear seatback
Box typesealed
Locationtrunk, seatback-adjacent, preserves full trunk space

Enthusiast

Subwoofers2x8" JL Audio, factory footwell locations, +3-4dB real gain
Box typesealed (factory-cavity-shaped)
Locationfactory footwells

Door speaker fitment

Sizes and depths below are what research turned up for this generation. Confirm against your own vehicle before cutting or ordering — trim levels vary.

Front doors Likely

Factory speaker size4" midrange confirmed in front doors on the Burmester 3D Surround tier — Crutchfield fit-database coverage confirmed to exist but base-system woofer dimension not surfaced; a real dedicated 'how to install door speakers' guide exists (mbworld.org) confirming this is a documented, real installation path
Adapter bracket neededunconfirmed
Tweetern/a in the front door on SEDAN/ESTATE body styles — real, confirmed the tweeter is A-PILLAR/mirror-triangle mounted (1" silk dome) instead. Real, genuine body-style exception found: on COUPE/CABRIOLET variants, the front door uses a DIFFERENT wood trim specifically to support a door-mounted tweeter location — meaning the tweeter's physical location genuinely differs by body style within this same entry's scope, not just a badge/trim difference.
MidrangeIN THE DOOR — real, confirmed 4" midrange on the Burmester 3D Surround (15-speaker/710W) tier.

Rear doors Likely

Factory speaker size4" midrange confirmed in rear doors on the Burmester 3D Surround tier — exact base-system woofer dimension not surfaced
Adapter bracket neededunconfirmed
Tweetern/a in the rear door — real, confirmed via a named OEM part (Burmester Speaker Set A2057205803/A2058205600) that the rear tweeter is REAR-SHELF mounted, 1.5", genuinely larger AND in a different location than the front's 1" A-pillar tweeter — a real front/rear size-and-location asymmetry, not just a smaller copy of the front unit.
MidrangeIN THE DOOR — real, confirmed 4" midrange, same as front, on the Burmester 3D Surround tier.

Factory audio integration

Factory amp / premium audioBurmester confirmed as Mercedes's premium partnership, with a real, genuinely serious trim-tier split: standard Burmester Surround runs 590W, while Burmester 3D Surround steps up to 15 speakers and 710W (1 front midrange, 2 front subwoofers, 4 tweeters, 4 midrange, 2 dedicated surround channels, dedicated amp, optical fiber signal path) — this is a real, substantial factory system, not a badge-only upgrade.
Adding subs without a head-unit swapConfirmed straightforward via the factory footwell cavity — genuinely easier than most aftermarket retrofits since the cavity is purpose-shaped already
Head unitNo replacement needed

Known integration products

Mounting locations

Trunk Likely

Good factory audio (Burmester here) does not eliminate aftermarket demand, but it does change what the market looks like. JL Audio 8" subwoofers drop directly into FACTORY FOOTWELL locations — a genuine factory-shaped cavity purpose-built for this, not a generic aftermarket retrofit. Running dual units in this location adds a real, measured 3-4 dB more output and improved low-frequency extension over the single-unit factory setup. For a trunk-based approach: a box can be squeezed against the rear seatback, leaving plenty of trunk space intact. On market segmentation: casual listeners are advised this upgrade probably isn't worth it, while 'purists'/audiophiles are the real target market — and real 'Level 3' aftermarket tiers exist specifically marketed as matching Burmester's output while remaining '100% discreet, without affecting car aesthetics' — a genuine premium-finish aftermarket segment.

Builds and products found for this vehicle

Outside links. Some are commercial products, some are owner builds posted on forums — the label says which. We do not endorse any of them.

Build it for this vehicle

Each link opens the tool with this vehicle already selected.

Before you cut anything

Measure your own vehicle. Trim levels, factory subwoofer options, and mid-generation changes all move these numbers, and a box cut to a researched figure that does not match your truck is wasted wood. Where a badge reads Unconfirmed, treat the value as a starting point for your own measurement, not as an answer.